Semiconductor device and manufacturing method thereof

Abstract

It is an object of the present invention to provide a peeling method that causes no damage to a layer to be peeled and to allow not only a layer to be peeled with a small surface area but also a layer to be peeled with a large surface area to be peeled entirely. Further, it is also an object of the present invention to bond a layer to be peeled to various base materials to provide a lighter semiconductor device and a manufacturing method thereof. Particularly, it is an object to bond various elements typified by a TFT, (a thin film diode, a photoelectric conversion element comprising a PIN junction of silicon, or a silicon resistance element) to a flexible film to provide a lighter semiconductor device and a manufacturing method thereof.When a metal layer 11 is provided over a substrate, an oxide layer 12 is provided in contact with the metal layer 11, a layer to be peeled 13 is formed, and the metal layer 11 is irradiated with a laser beam to perform oxidization and form a metal oxide layer 16, a clear separation is possible with a physical means within the metal oxide layer 12 or at an interface between the metal oxide layer 16 and the oxide layer 12.

Description

TECHINICAL FIELD[0001]The present invention relates to a peeling method of a layer to be peeled, especially, a method for peeling a layer to be peeled including various elements. In addition, the present invention relates to a semiconductor device that has a semiconductor integrated circuit or a thin film transistor (hereinafter referred to as TFT) transferred by sticking a separated layer to be peeled to a substrate, and a manufacturing method thereof. The invention relates, for example, an electro-optical device typified by a liquid crystal module, a light-emitting device typified by an EL module, and an electronics that has such a device mounted as a component.[0002]In the specification, the term, ‘semiconductor device’, generally indicates devices that are capable of functioning by utilizing semiconductor characteristics, and an electro-optical device, a light-emitting device, a semiconductor circuit, and electronics are all included in the semiconductor device.BACKGROUND ART[00...

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Benefits of technology

[0046]According to the present invention, irradiation of a laser beam, heat treatment, or compound treatment of irradiation of a laser beam and heat treatment is performed to a metal layer for performing oxidation treatment, with the result that a metal oxide layer is formed to make it possible to peel a layer to be peeled easily from a substrate with a physical means. In laser irradiation in the oxidation treatment, damage is not caused to a semiconductor layer since the laser irradiation is performed to the metal layer from the substrate side in the case of having no desire to damage the semiconductor layer.

[0047]Further, according to the present invention, it is possible to peel entirely with a high yield not only a layer to be peeled with a small area but also a layer to be peeled with a large area.

[0048]In addition, according to the present invention, peeling can be easily performed by a physical means, for example, by a human hand. Therefore, the process can be said to be appropriate for mass production. Further, in the case of manufacturing a manufacturing system for peeling a layer to be peeled in mass production, a large-scale manufacturing system can also be manufactured at low cost.

Problems solved by technology

However, the substrate used for the previous image display device is a substrate comprising an inorganic material such as a glass substrate or a quartz substrate, as described above, and there are defects of breaking and being heavy, which are unique to the inorganic material.

Compared to the substrate such as the glass or quartz substrate, however, the substrate such as the plastic film has low heat resistance, and therefore, a processing temperature in manufacturing a TFT is limited.

In the result, it was difficult to manufacture a TFT directly on the plastic film, which has favorable characteristics compared to the TFT formed on the glass or quartz substrate.

Consequently, a high-performance image display device or light-emitting device that uses a plastic film has not been realized.

However, since amorphous silicon or polycrystalline silicon is used as the separating layer in the aforementioned method, a problem is considered that an irradiated laser beam is transmitted through the separating layer depending on a film thickness thereof and a wavelength of the applied laser beam to damage the layer to be peeled.

Further, in the aforementioned method, in the case of forming an element on a separating layer, hydrogen contained in the separating layer is diffused and decreased when a heat treatment at a high temperature is carried out in the process of manufacturing the element.

As a result, there is the possibility of insufficient peeling even if the separating layer is irradiated with a laser beam.

Therefore, there is a problem that the process after forming the separating layer is limited in order to retain of the amount of hydrogen contained in the separating layer.

Additionally, it is difficult to peel a layer to be peeled with a large surface according to the aforementioned method.

Although the aforementioned publication gives a description of forming a light-shielding layer or a reflection layer in order to prevent the layer to be peeled from being damaged, in that case, it becomes difficult to fabricate a transmission type liquid crystal display device.

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